Many people wonder if they should fully drain their laptop battery before recharging it. The answer depends on the type of battery.
In the past, laptops often used nickel-cadmium (NiCad) batteries, which had a problem called the "memory effect." If these batteries weren't completely discharged before being recharged, they would "remember" the charge level they reached, causing them to act as if they were fully drained at that level in the future. This could reduce the battery's lifespan, leading to the need for a replacement much sooner than expected. Therefore, if someone still has a laptop with a NiCad battery, it was recommended to let it discharge fully before recharging.
Today, very few laptops use NiCad batteries. The next type, nickel-metal-hydride (NiMH) batteries, were an improvement because they were less affected by the memory effect. However, they generally had a shorter lifespan.
Most laptops now use lithium-ion (Li-Ion) batteries, which are much better and longer-lasting. Like NiMH batteries, Li-Ion batteries don’t have the memory effect, so they can be charged at any time. In fact, they last longer if they are not allowed to fully discharge.
Another advantage of lithium-ion batteries is their ability to hold a charge. Unlike older battery types that lose charge quickly—even when the laptop is turned off—lithium-ion batteries can retain their charge for months with only a slight decrease.
In short, if a laptop has a lithium-ion battery, there’s no need to let it drain completely before recharging. Doing so could actually shorten its lifespan.
To find out what type of battery a laptop has, users can either remove the battery (if possible) to check the label or, for newer laptops where access to the battery is not straightforward, a quick search online using the laptop’s brand and model will provide the necessary specifications.